Machine protective apparatus



Sept. 11, 1945. c. A. WIKEN ETAL 2,384,512

' MACHINE PROTECTIVE APPARATUS Filed Jan. 5, 1944 2 Sheets-Sheet 1ravaawama INVENTORS CHRISTVA. IKEN ERIC A RE! 5/6 ATTORNEY p 1945' c. A.WIKEN ETAL 2,384,512

MACHINE PROTECTIVE APPARATUS.

Filed Jan. 5, 1944 2 Sheets-Sheet 2 INVENTORS cH/P/f) A W/mF/V, awa- A.RAVE/6, BY

ATTORNEYS Patented Sept. 11, 1945 UNITED STATES PATENT. OFFICE 2 Claims.(01. s1-2ss) This invention relates to protective coverings and isparticularly concerned with expansible and contractible protectivecoverings capable of enclosing surfaces, machine parts and the like ofvariable extent.

Machine parts such as feed screws, slide guide surfaces and the likethat usually have exposed lubricated areas collect considerable foreignmatter such as abrasive dust and dirt which causes wear and otherwiseinterferes with efficient operation. The invention has specialapplication for the protective covering of such parts during all workingconditions without interfering with normal operation or preventinglubrication and other normal treatments of such parts.

It is a major object of the invention to provide novel extensible andcontractible covering arrangements for machine surfaces and parts andthe like of variable extent.

A further object of the invention is to provide novel arrangements forpreventing the intrusion of dirt, dust, moisture and the like to guide,hearing and like surfaces of variable extent without interfering withnormal functioning of such surfaces.

It is a further object of the invention to provide a novel tubularprotective casing which is longitudinally, or axially flexible butsufliciently strong to substantially support itself against longitudinalbending even when fully extended, and which maintains a substantiallyuniform inner diameter during all conditions of expansion andcompression.

It is a further object of the invention to provide a novel expansibleand collapsible covering adapted to extend over parts normally exposedto variable extent by relative displacement of two members regardless ofthe relative disposition of said members.

It is a further object of the invention to provide a novel expansibleand collapsible casing adapted to be supported at opposite ends byrelatively adjustable members for extending over parts between saidmembers without interfering with normal operation thereof.

A further object of the invention is to provide a novel hollowprotective covering wherein a sleeve of fabric or the like is mounted ona longitudinally expansible and contractible open-ended supporting form.

It is a further object of the invention to provide a novel protectivecovering wherein a sleeve of novel protective covering means for a feedscrew which is extensibleand contractible with correspondng adjustmentof said screw without interfering with such adjustment.

Further objects of the invention will presently .appear as thedescription proceeds in connection with the appended claims and theannexed drawings wherein:

Figure 1 is an elevation somewhat diagrammatically illustrating theinvention as applied to a vertical feed screw of a grinding machine;

Figure 2 is an enlarged elevation partly in section illustrating chieflythat a protective feed screw covering of the invention may be readilycollapsed for oiling and like operations;

Figure 3 is an enlarged side elevation, mainly in section, illustratingdetails of protective coverings according-to a preferred embodiment ofthe invention as used on a horizontal feed screw in the machine ofFigure 1;

Figure 4 is a fragmentary view partly in section taken along line 44 ofFigure 3 illustrating attachment of the horizontal feed screw to thetable shifted thereby;

Figure 5 is an enlarged elevation, partly in section, illustratingdetails of construction of a protective covering of Figure 3 at one end;Figure 6 is a rather diagrammatic elevation, partly in section,illustrating the invention as applied to telescoping members, Figure '7shows further a modification and Figure 8 is a fragmentary verticalsection through another modified form of Table assembly I2 is providedwith a work surface l5 for supporting work to be engaged by a grindingwheel I6 suitably mounted and driven in a grinder assembly I! whollycarried by a split collar [8 which is slidably adjustable along acylindrical vertical column is rigidly upstanding from base H. Collar i8is formed with aligned lugs in which is threaded a screw 20 rotatable byhandle 2|. By manipulation of handle 2i, to turn screw 20, collar it maybe expanded an integral ear 23 in which is journaled the cylindricalshank 30 of a vertical lift feed screw 24, as illustrated in Figure 2.Enlarged rigid collars or formations 25, 26 on screw 24 prevent axialdisplacement of screw 24, which is threaded into an car 21 rigid withcollar I8. After handle 2| has been turned to release collar l9, thelatter may then be vertically displaced by rotation of handle 28 of feedscrew 24 to raise or lower grinding wheel [6 as desired with respect towork surface l5.

The above described grinder apparatus is disclosed and claimed in ourcopending application Serial No. 467,512 filed December 1, 1942, towhich reference is made for any further detail.

According to one phase of the invention the threads of feedscrew 24 areprotectively enclosed by flexible extensible and collapsible tubularcasings 29 and 3| during all conditions of adjustment of screw 24.

As illustrated in Figure 2, flexible casing 29 extends under compressionbetween ears 23 and 21 and is longitudinally or axially resilient sothat its lower end may followear 21 during all vertical adjustmentsSimilarly, flexible casing 3| extends under compression between ear 21'and a suitable support rigid with the end of screw 24 and islongitudinally resilient so that its upper end may also follow ear 21during all vertical adjustments.

Flexible casings 29 and 3| are like Sylphons, and will probably presentexteriors which are more wrinkled than illustrated in Figure 2 whencompressed by adjustment of feed screw 24 or by the operator's hand topermit oiling of the threads as illustrated, but it will be appreciatedthat the drawings are illustrative only and both casings are ofsuflicient longitudinal extent to cover the feed screw threads in bothextremes of vertical adjustment. The same applies to Figure 3 describedbelow.

Casings 29 and 3|. may also be employed as protective coverings for thehorizontal feed screw as illustrated in Figure 3. Since Figures 3 andillustrate casings 29 and 3| in considerable detail, description of thelatter will now proceed in connection with Figures 3-5.

The front wall of base II is formed with a 1101-- low boss 33 forreceiving a support collar 34 in which is journaled the cylindricalshank 35 of a horizontal feed screw 36. Axial displacement of screw 36is prevented by suitable enlarged stop members 31, 38 pinned orotherwise made rigid therewith. Outside base ll, shank 35 has securedthereto a graduated disc 39 and a hand wheel 4|. An index 42 forcooperation with disc 39 is secured to base II by a machine screw 43which also holds collar 34 immovable in boss 33.

A bracket 44,.Lbolted to the underside of table assembly l2, extendsdownward through a suitable slot in base II and is formed with a boss 45into and through which screw 36 is threaded. When wheel 42 is rotated,table assembly I2 is displaced. The above briefly described constructionand operation of the apparatus of Figures 3 and 4 is also disclosed insaid Serial No.

comprises a tubular sleeve 49 of some dust and moisture proof fabricsuch as heavy canvas and surrounds an axially expansible contractiblehollow supporting form such as a cylindrical fine wire coil spring 49.As illustrated in Figure 5.

each end of sleeve 48 is turned over the end coil of spring 49 andsecured thereto as by stitching .5|. The length of sleeve 49 is chosenso as to be at least slightly greater than required for extreme outwardadjustment of boss 45, and spring 49 is rotates without interferencefrom casing 29 since away from the screw threads.

collar 34 and face 59.

If desired, retainers 52 and 53 could be made for press-fitting withstop 39 and shoulder 46, but this is not needed if spring 49 issufiiciently strong. The main functions of stop 39 and the 4|)cylindrical face of shoulder 46, so far as casing 29 467,512 to whichreference is also made for furis concerned, are to prevent accidentalradial displacement-of retainers 52, 53 into engagement with the screwthreads. However, especially for vertical feed screws such as in Figure2; such cylindrical shoulder faces may be eliminated if desired, sincethe retainers need be urged against axially facing surfaces only.

The free end of screw 36 is formed with a tapped bore in which isthreaded a bolt 54. The shank of bolt 54 projects a considerabledistance from the end of screw 36 freely through a suitable aperture ina cup-shaped sheet metal retainer 55. Retainer 55 is partly supported bybolt 54 which is rotatable relative thereto. A suitable flat washer 56is interposed between the head of bolt 54 and retainer 55 for providingadded slippage between them.

Casing 3| surrounding screw 36 has its opposite ends nested withinretainer 55 and a retainer 51 seated against the vertical face ofshoulder 41. Casing 3| comprises a sleeve 56, similar to sleeve 49,surrounding a cylindrical compression spring form 59 similar to spring49. The lengths of sleeve 53 and spring 59 are chosen as above explainedin connection with casing 29. Casing 3| is thus maintained underlongitudinal compression substantially between boss 45 and screw 36.

When screw 36 is rotated. the opposite ends of easing 3| aresimultaneously axially displaced in opposite directions. Retainer 51 ismaintained tight against shoulder 41 during such rotation of screw 36,but there must be relative rotation between bolt 54 and retainer 55 toprevent undesirable turning of easing 3|. This is accomplished byselecting a compression spring 59 which is by suitably proportioning theparts, and retainer 55 is thereby'maintained against rotation to keepcasing 3| from undesirable turning and twisting.

Similarly to casing 29, casing 3| extends over the end threads of screw36 during all adjustments. The projecting length of bolt 54 beyond theendpf screw 36 is selected to accommodate collapsed casing 3| when screw24 is adjusted to its extreme to the left.

Casing 3|, in'F'igure 2, has its lower end connected to the end of screw24 in the same manner as it is connected to the end of screw 36 inFigure 3.

With no protective'casings on screw 36, the latter may be pulled outthrough boss 33 by turning screw 36 until it clears boss 45, afterremoving screw 43.

For assembling casings 29 and 3| on screw 36, the latter is insertedthrough boss 33 until its free end is about halfway between collar 34andboss until bolt 54 can be secured to the end of screw 36. In eachinstance, before casing 23 or 3| is assembled over the screw, the screwthreads are greased very liberally. The reverse operation takes placewhen it is desired to remove the casings.

Casings 29 and 3| when assembled for use as in Figures 2, 3 and 6 aresubstantially self support ing longitudinally by reason of theircompression. In fact, even when removed from the machine assembly andpermitted to fully expand, casings 29 and 3| substantially supportthemselves against longitudinal bending. Casings 29 and 3| also maintainsubstantially a fixed internal diameter regardless of compression andexpansion, to prevent contact with the threads protectively enclosedthereby.

Figure 6 illustrates application of the invention to protection of thenormally exposed slide guide surface 80 between two relatively axiallyslidable telescoping tubes 6| and 62. Here casing 29 extends undercompression between a fiat face on a collar 63, secured to tube 62 as byset screw 63, and an opposed parallel flat shoulder face at 65 on tube3|.

In Figure 7 we have shown a further modification of the invention inwhich the grinder of Figures 1 and 2 is provided with a pair of bootswhich protect both the raising and lowering screw 23 and the column l3.In this instance collar |8a is of modified form, being of sufficientsize to provide a chamber for the lower end of the lifting screw and hasannular top and bottom faces 72 and I3, respectively. Cap 220. issimilarly enlarged to provide an annular, downwardly directed face 15.Machine base is also provided with an upwardly directed face 15.

Telescoped over the column, above and below collar I811, and enclosingthe exposed portions of both the column and lifting screw, are a pair ofexpansible and contractible boots I6 and 11, respectively, havingexpanding springs 18 and against surfaces 12 and 14 of collar Na and cap22a, respectively, and the retainers of boot 11 seat against faces 13and 15 of the collar and base,

respectively, to seal the boots against ingress of dust or otherextraneous material, in a manner similar to the forms of boot previouslydescribed,

it being understood that the boots may be slid back for inspection oroiling against the action of their springs. The retainers seatingagainst the collar are provided with enlarged apertured portions 32 and33 thro;.gh which screw 24 projects.

It is accordingly apparent that by using a pair of comparatively-largediameter boots both the column and lifting screw are adequately guarded,and it is to be understood that it is not absolutely essential to employboots of cylindrical form. For instance, where the parts to be guardedare of assymmetrical shape, and it is desired to make the boot assemblyas compact as possible, it may be given a configuration approximatingthat of the parts to which it is applied, provided that the departurefrom cylindrical form is not so great as to impair the action of theexpander spring or to sealing caps 8|. The retainers of boot 76 seatotherwise adversely affect the sealing action of the boot.

In all of the above described embodiments of the invention, the flexibletubular casings are longitudinally compressed substantially betweenrelatively movable members, and the casings expond or collapse withrelative movement of the members so as to maintain their protectivecovering without interfering with normal operation of the members. Thecasings are under such strong axial compression, even during extremeseparation of the members, that they are dust and dirt tight. Ifdesired, the retainers could be secured to the ends of the casings tofacilitate assembly. The relative sizes of the members is alsoimmaterial to the invention.

In some instances, especially where, as illus trated in Figures 1, 2and'7, the element or elements to be guarded are substantially vertical,the spring may be omitted and gravity forces relied upon to cause theboot to hang out of contact with the guarded element in response to therelative movement of the two members with which the boot is associated.Such a device is shown in Figure 8 and comprises a ring or plate 8|asuitably sewed ont each end of boot I6, the upper ring or plate beingsecured as by screws 9| or other suitable means adjacent the upper partof the column or other member to be guarded, and the lower ring or platebeing left free so as to gravitationally rest on the upwardly facingsurface with which it, cooperates. In this form of the invention thematerial of the boot may be allowed to fall in random folds as the partsto be guarded are moved toward each other or, if desired, fold lines orcorrugations may be formed in the material beforehand, so as to insurefolding of the boot in a predetermined manner during operation.Lubrication or inspection of the column or other member may readily beeffected by grasping the free member 8|a and collapsing the boot in themanner heretofore described.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range orequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

1. In combination with a shittable member and a rotatable feed screwthreadedly connected thereto and projecting from opposite sides thereof,longitudinally flexible tubular casing means surrounding the exposedthreads of said screw, said casing being expansible and contractible soas to beautomatically maintained axially coextensive with said screwduring all conditions of operation, and said casing means maintainingsubstantially uniform inner diameter during said conditions so as toavoid engagement with said feed screw threads.

2. A device for protectively enclosing normally exposed threads of arotatable feed screw threadedly connected to a member to be movedthereby and having a free end projecting beyond said member comprising aretainer rotatably mounted at said free end of said teed screw, anaxially flexible hollow casing surrounding'said feed screw and seated atopposite ends on said member and said retainer so as to provide acovering for the threads of said feed screw beyond said memberregardless of the position of said member, said retainer preventingrotation or twisting of said covering when said feed screw is rotated.

CHRISTY A. WIKEN. ERIC A. REIBIG.

